Insole and method of making the same



1942- F. R. MERRITT. 2,302,789

INSOLE AND METHOD OF MAKING THE SAME I Filed Nov. 22, 1940 ZSheets-Sheet 1 Nov'. 24, 1942. F, R. MERRITT 2,302,789

INSOLE AND METHOD OF MAKING THE SAME Filed Nov. 22, 19 2 sksheet 2 54 55 IT /l u 6 V y "i Patented Nov. 24,1942

T OFFICE.

2,302,789 INSOLE ANflM'ETHOD OF MAKENG THE SAME Frank E. Merritt, Haverhill, Mass, assignor to United Shoe Machinery Corporation, Flemington, N. J a corporation of New Jersey Application November 22, 1940, Serial No. 366,622

13 Claims.

This invention relates to improvements in insoles and methods of making the same.

In the manufacture of welt shoes it is common to employ an insole provided with a marginal sewing rib and having a piece of reinforcing fabric applied to its ribbed side to prevent undue stretching of the insole and to strengthen the sewing rib so as to afford a more secure anchorage for the inseam stitches. Such reinforced insoles, however, are often found to be unduly stiff so that they fail to permit such bending of the forepart of the shoe as is desirable to enable the shoe to accommodate itself to the flexure of the foot which takes place when the wearer of the shoe is walking.

One object of the present invention is to provide insoles having a sufiicient degree of flexibility in their foreparts to enable them to bend as required.

The invention is herein illustrated in its application to reinforced ribbed insoles for use in the manufacture of welt shoes, although in certain aspects the invention is not thus limited but is applicable to the manufacture of insoles for use in other types of shoes.

The invention will be explained with reference to the accompanying drawings, in which Fig. 1 is a perspective view of my improved insole showing the upper or foot-facing side of the insole and showing the insole as it appears when it is in a substantially fiat condition;

Fig. 2 is a bottom view of the insole illustrated in Fig. 1, the insole being shown in a flat condition;

Fig. 3 is a fragmentary sectional View taken along the line IIIIII of Fig. 1, but showing the insole forepart in the curved or flexed condition which it normally tends to assume;

Fig. 4 is a cross-sectional view of the insole taken along the line IVIV of Fig. 1;

Fig. 5 is a longitudinal sectional view of the body portion of the insole as it appears at one stage in its manufacture;

Fig. 6 is a view similar to Fig. 5 but illustrating a further stage in the manufacture of the insole;

Fig. '7 is a longitudinal sectional view of the insole in the course of its manufacture illustrating how the reinforcing fabric is applied;

Fig. 8 is a longitudinal sectional view of the insole illustrating the step of applying a covering layer to its foot-facing side;

Fig. 9 is a perspective view of an insole illustrating an alternative construction;

Fig. 10 is a fragmentary perspective view of the body portion of the insole shown in Fig. 9;

Fig. 11 is a fragmentary sectional view on the line XI-XI of Fig. 9; and

Fig. 12 is a cross-sectional view of a shoe embodying my improved insole.

In the manufacture of my improved insole I prefer to make the body portion. 14 of the insole of a good grade of sole leather having a grain surface is and a flesh surface l8. To promote flexibility in the forepart of the insole I find it desirable to form a shallow central recess in the flesh side thereof, as clearly shown in Figs. 1 to 6, inclusive, the purpose of the recess being to provide a relatively thin and consequently more flexible portion in the central forepart of the insole. Either before or after forming the recess 20 the insole is channeled at its flesh side in any well-known manner to provide inner and outer marginal channel lips 22 and 24, respectively, and a marginal feather 25. as shown in Fig. 5. To provide a sewing rib which will not unduly stiffen the insole I roll the outer channel lip 24 back and adhesively secure it over the between substance 26, as illustratedin Fig. 6. I find it undesirable, however, to raise the inner channel lip 22 to any substantial extent and advantageously the inner lip may be left in the position it occupies at the completion of the channeling operation, in which position it is shown in Figs. 5 and 6.

In order further to increase the flexibility of the forepar't of the insole I remove a thin layer of material from the relatively stiff upper or grain side of the insole and replace this layer with a covering piece 48 (Fig. 1) of limp material such, for example, as soft upper leather of a thickness corresponding to that of the removed layer. To effect the removal of this layer of material from the grain side of the insole I prefer to split the insole from its toe end to its shank portion in a plane a short distance below the grain surface of the insole, as indicated at 28 in Fig. 5, thereby forming a grain-surfaced leaf 3%] which is left connected with the body portion of the insole at 32 and subsequently to sever the leaf 3% from the body portion, making a transverse cut oblique to the insole surface near the junction of the leaf 3E! with the shank portion of the insole so as to leave a narrow flap M (Fig. 6) having a beveled under surface at and a thin free edge 38, the purpose of this flap 34 being to overlap the rear margin of the covering piece as will later appear. After the insole body has been prepared as already described, it is ready to have a layer of reinforcing fabric 42 applied to its ribbed side and to have the above-mentioned covering piece 40 applied to the surface at the opposite side of the insole which was left exposed by the severing of the leaf 3U. Before either the reinforcing fabric or the covering piece is applied, however, the insole is flexed to impart 'to its forepart substantially the same curvature as that which it will assume when, after having been incorporated in a shoe, it is bent approximately to a maximum extent in accommodating itself to the flexure of the foot, and both the reinforcing fabric and the covering piece are applied to the insole while the latter is maintained in this flexed condition.

Advantageously the reinforcing fabric 42 may be first applied to the insole and the insole may be flexed by conforming it to the curved upper surface of .a form '44 and the form may be utilized to support the insole, and thus to maintain it in flexed condition, while the fabric is being applied. The reinforcing fabric, which may be a layer of canvas precoated upon one side with pressure responsive cement, is then superposed upon the insole and pressed smoothly against the portion of the insole surface which lies Within the sewing rib, after which the marginal portions of the fabric are formed in to the angle at the base of the inner channel lip 22 and also pressed against the inner side of the lip. This formingin operation may be effected manually while the insole is upon the form or it may be accomplished later by the use of a suitable machine and after the fabric has been secured to the channel lip any surplus fabric extending beyond the lip is trimmed off. The reinforced lip 22 together with the folded back lip 24 constitute a sewing rib 21 which is adapted to lie substantially in the plane of the insole when the insole is incorporated in ,a shoe and therefore has no tendency to impart stiffness to the insole or the shoe.

The reinforcing fabric having been attached to the insole while the insole was in a condition a of greatest flexure, it will be apparent that the fabric is under no tension lengthwise of the insole while the latter is in such a flexed condition and that subsequent flexing or bending of the insole will entail no stretching of the fabric. quently the fabric will not resist the bending of the insole as it would if it had been secured to the insole while the latter was in a flat condition.

The covering piece 40 is applied to the unribbed side of the insole to replace the grain-surface layer removed therefrom. The covering piece may consist of a piece of soft limp upper leather such as kid or sheepskin and it is cut sufficiently larger than the forepart of the insole to provide a marginal allowance for covering the edge and the marginal surface portion at the flesh side of the insole. In order that no wrinkles shall be formed in the covering piece, such as might cause discomfort to the foot when the insole is flexed, the covering piece is preferably applied to the insole while the latter is in substantially the same condition of flexure as when the reinforcing fabric is applied thereto. As shown in Fig. 8, the insole may be supported while the covering piece 40 is being applied to it upon a form 46 having an upper surface which is curved so as to be complemental to the curvature of the form 44. After an adhesive has been applied, either to the side of the covering piece which is to be attached to the insole or to the corresponding surface of the insole. the covering piece is overlaid upon the forepart of the insole, as shown in Fig, 8, and pressed smoothly against the insole, the rear portion of the covering piece being laid beneath the insole flap 34 and the latter is subsequently se- Consecured by cement to the upper side of the covering piece. Preferably the portion of the covering piece which extends beneath the flap 34 is skived to a thin edge so that no undesirable bulge will be formed in the flap 34. The insole is then removed from the form 45 and the extended marginal portion of the covering piece 44 is folded over the edge of the insole and pressed against the flesh side of the insole feather so that the edge of the covering piece abuts the shoulder at the base of the outer channel lip 24.

Instead of removing a grain layer from the entire forepart of the insole I may cut away the material at the grain side of the ball portion only, as illustrated in Figs. 9 to 11, inclusive, leaving the toe portion of the insole forepart unreduced and leaving a flap 340 (corresponding to the flap 34 already described) at the forward extremity of the shank portion, and a second flap 48 at the rear extremity of the toe portion for overlying the rear and forward margins respectively of a covering piece 400 subsequently to be employed to replace the cut-away insole material. The covering piece 400, like the covering 40, is made of soft limp material of greater flexibility than that of the grain-surfaced sole leather material which was cut away and the covering piece 4939 is cut wide enough to extend beneath the flaps 34 0 and 48 and long enough to overextendthe opposite edges of the ball portion of the insole. This covering piece 400 is cemented to the reduced ball portion of the insole and the end portions of the covering piece are folded over and secured by cement to the edge portions of the insole and to. the flesh side of the insole feather. The insole flaps 348 and 48 are then cemented to the exposed surface of the covering piece and so that the edges of the latter will not come in contact with the foot.

As shown in Fig. 12, the improved insole herein described may be used in the manufacture of a welt shoe in the same manner as a conventional ribbed insole, an upper 58, together with a welt 52, being secured by means of inseam stitches 54 to the reinforced sewing rib 21 and an outsole 53 being secured, as by means of outseam stitches 58, to the welt.

If an insole, such as that shown in Figs. 9 and 11, is to be used in the manufacture of a welt shoe, the insole will be provided upon its flesh side with a marginal sewing rib and preferably the rib will be formed and reinforced with fabric in the same manner as that h-ereinbefore described, the insole preferably being maintained in a condition of maximum flexure while the reinforcing fabric and the covering piece are being applied.

Because of the several features herein described my improved insole is much more flexible in its forepart than insoles of the type ordinarily employed in welt shoes. The removal of the relatively stiff grain-surfaced layer from the side of the insole which is to face the foot and its replacement by soft, limp covering material not only contributes substantially to the production of flexibility but also provides a smooth soft surface for engagement with the foot and makes unnecessary the use of a sock lining in the shoe. The provision of a flap integral with the shank portion of the insole for overlying the rear edge of the forepart covering. and the provision of a second insole flap for overlying the forward edge of the insole covering where the latter is confined to the ball portion only of the insole serves to prevent the edges of the covering from causing discomfort to the foot and insures against possibility of the covering becoming loosened or curling up at its edges while the shoe is being worn. Inasmuch as this forepart covering is cemented to the insole while the latter is in a flexed condition any tendency of the covering to become wrinkled or distorted during the flexing of the shoe in use is eliminated. The flexibility of the forepart of the insole is also enhanced by my method of cementing the reinforcing fabric to the insole while the forepart of the latter is maintained. under flexure since the fabric will not be stretched lengthwise of the insole during flexing of the insole in the shoe and thus will offer no resistance to such flexing. The re-cessing of the insole forepart at its outsole-facing side and the provision of a sewing rib having no upstanding lip portions to stiffen the insole are further factors which assist in insuring exceptional flexibility in the insole.

Having described my invention, wh at I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in the manufactureof reinforced insoles which comprises removing a layer of material from each side of the forepart of an insole blank thereby substantially reducing the thickness of said forepart and decreasing its resistance to bending stress, flexing the reduced insole blank to impart to its f-orepart substantially the same longitudinal curvature as that it will as-- sume when, after having been incorporated in a shoe, it is bent approximately to a maximum extent in accommodating itself to the flexure of the foot, and securing a reinforcing layer to the longitudinally convex side of the insole and a covering layer to the longitudinally concave side of the insole while maintaining said blank in said flexed condition.

2. That improvement in the manufacture of insoles which comprises providing an insole having a feather and a marginal sewing rib, substantially reducing the thickness of the insole in the vicinity of its ball portion, flexing the ball portion of the insole so that it is longitudinally convex at its ribbed side, supporting the insole in uch flexed condition with its ribbed side uppermost, adhesively securing a layer of reinforcing material to the ribbed side of the insole while it is thus supported, inverting the insole and supporting it in said flexed condition with its unribbed side uppermost, and while the ins-ole is thus supported securing to the forepart of its upper side a covering layer which is larger than the insole and securing the marginal portion of said layer to the edge and to the lower side of the feather.

3. That improvement in the manufacture of in soles which comprises removing a layer of ma terial from the forepart of an insole at the side which is to face the foot, flexing the insole to impart to its forepart substantially the same longitudinal curvature as that it will assume when, after having been incorporated in a shoe, it is bent approximately to a maximum extent in accordmodating itself to the flexure of the foot while maintaining the insole in such flexed condition cementing a layer of covering material to the forepart of the ins-ole to replace said removed layer and also cementing a layer of reinforcing material to the opposite side of the insole.

l. That improvement in the manufacture of insoles which comprises splitting an insole from its toe end to its shank portion thereby providing upper and lower layers in its forepart which are integral with the shank portion of the insole, re-

moving the forward portion of said upper layer but leaving a narrow rear portion thereof to form an integral flap at the forward end of the shank portion, cementing a layer of reinforcing fabric to one side of said lower layer while the insole is supported in a longitudinally curved condition, and while the insole is being still maintained. i said condition cementing to the other side of said lower layer a layer of covering material having its rear portion extending beneath said flap, and cementing said flap to said covering material.

5. That improvement in the manufacture of flexible insoles which comprises providing an insole having a marginal sewing rib and a forepart recess the rib-bed side of the insole at the inner side of said rib, removing material from the unribbed side of the insole thereby further reducing the insole thickness at the ball portion, cementing reinforcing fabric to the recessed insole surface and to said rib, and cementing a covering layer to the ball portion at the unribbed side of the insole to replace the material removed from that side.

6. That improvement in the manufacture of flexible insoles which comprises recessing the central forepart portion of a grain-surfaced leather insole at the flesh side of the insole and removing a layer of substantial thickness the grain side of the forepart of the insole thereby forming a relatively thin and flexible cen ral portion in said forepart having an exposed flesh surface at that side which is to face the foot, covering said surface with a piece of sheet material having greater flexibility than the removed layer and having a marginal portion extending beyond the relatively thick marginal portion of the insole, and folding said marginal portion of said covering piece over the edge of the insole and cementing it to the marginal portion of the opposite side of the insole.

7. An insole comprising a body portion of insole leather having a grain-surfaced heel and shank portion and a forepart from which the relatively stiff grain surface material has been removed and the central partion of which is recessed at its flesh side, and a piece of soft limp sheet material covering the grain side of the insole forepart to replace the removed material.

8. An insole comprising a body portion of sole leather having a grain-surfaced shank portion and having its ball and toe portions reduced at the grain side of the insole by the removal therefrom of a surface layer of substantial thickness, and a covering cemented to the reduced side of said forepart and consisting of a thin piece of soft limp upper leather having greater flexibility than said surface layer.

9. An insole comprising a body portion of sole leather having a grain surfaced shank portion and having its ball and toe portions reduced at the grain side of the insole by the removal there from of a surface layer of substantial thickness, a covering overlying the reduced side of said forepart consisting of a thin layer of material of greater flexibility than said surface layer, said covering overlying and being adhesively secured to the edge of said ball and toe portions, and a narrow flap integral with said shank portion overlying the rear portion of said covering.

10. An insole comprising a body portion of sole leather having grain surfaced shank and toe porticns and having a ball portion reduced at the grain side of the insole by the removal of a surface layer of substantial thickness, and a soft, limp layer of material cemented to and covering the reduced side of said ball portion, said layer covering also both lateral edges of said reduced ball portion and the marginal portion of the surface at the unreduced side of said ball portion.

11.. An insole comprising a body portion of sole leather having grain-surfaced shank and toe portions and having a ball portion reduced at the grain side of the insole by the removal of a surface layer of substantial thickness, said insole having at its flesh side a marginal sewing rib comprising an inner channel lip disposed in a substantially umaised position and an outer channel lip adhesively secured in overlying relation to the substance between the channels, a soft, limp layer of material cemented to and covering the reduced side of said ball portion, a narrow flap integral with said shank portion cemented to the rear extremity of said covering piece, and a narrow flap integral with said toe portion cemented to the forward extremity of said covering piece.

12. An insole comprising a body portion of sole leather having a grain-surfaced shank portion and having its forepart reduced at its grain side by the removal therefrom of a surface layer of substantial thickness, said insole having a marginal sewing rib at its flesh side and having a central forepart recess inwardly of said rib in its flesh side, a layer of reinforcing fabric cemented to the flesh side of the insole inside of the sewing rib and to the inner side of said rib, and a covering of soft, limp material cemented to the reduced side of said forepart.

13. That improvement in the manufacture of insoles which comprises providing a leather insole having a grain surface at one side and a marginal sewing rib at the other side, splitting the insole from its toe end rearwardly to its shank portion in a plane a short distance below the grain surface thereby forming a grain surfaced leaf connected at its rear extremity with the body of the insole, making a transverse oblique cut extending downwardly and rearwardly through the rear portion of said leaf thereby severing the greater portion of the leaf from the insole but leaving a narrow flap integral with the insole and having a thin edge at its free extremity, placing said insole ribbed side uppermost upon a form having an insole shaping surface curved to correspond approximately to the maximum longitudinal curvature which the insole will assume in accommodating itself to the flexure of a foot in walking and conforming the insole to the curvature of said form, reinforcing said sewing rib by adhesively securing a layer of fabric to the insole surface within said rib and to the inner side of said rib while maintaining the insole conformed to said form, inverting the insole and placing it, ribbed side lowermost, upon a second form having a, curved insole supporting surface complemental to that of the first form and, while the insole is supported upon the second formand maintained thereby in the same curved condition as when on the first form, adhesively securing a covering layer to the unribbed side of the forepart of the insole and adhesively securing said flap in overlapping position upon the rear margin of said covering layer.

FRANK R. MERRI'IT. 

